.box {
    width: 100px;
    height: 100px;
    margin: 20px auto 0;
    background-color: aqua;
    border-top: 4px solid black;
    border-right: 5px solid black;
    border-bottom: 6px solid black;
    border-left: 7px solid black;
    box-sizing: border-box;
}